1. Field of the Invention
The present invention relates to a switch operating mechanism in which an operator turns a switch on and/or off by pressing the switch provided at a circuit board.
2. Description of the Related Art
Some automobile steering wheels are equipped with, for example, a switch for shifting gears. Among such switch operating mechanisms, there is a type which is arranged to activate the switch by moving the operating knob upward so that the switch can be operated while an operator is holding the steering wheel.
A switch operating mechanism 50 of this type includes a circuit board 12 with a switch 14 (a contact member held by rubber) and an operating knob 54 that is supported by a spindle 52 so as to rotate about the spindle 52, which is provided at a lower position than the switch 14 as schematically illustrated in FIG. 4B. When the operator moves the operating knob 54 upward, the operating knob 54 rotates about the spindle 52, and a front end 54A of the operating knob 54 presses a pusher 56 downward, thereby turning the switch 14 on and/or off (i.e., a hinge-type operating knob).
However, the conventional switch operating mechanism 50 has some drawbacks. The operating knob 54 is cranked to operate the switch 14. Further, since the switch operating mechanism 50 is supported by a spindle provided at a lower position than the switch 14, the front end 54A of the operating knob 54 (the portion of the operating knob that presses the pusher 56) moves along an arcuate path around the spindle 52. Components of the pressing force act not only in an axial direction of the pusher 56 but also in a direction perpendicular thereto, and the relationship between a force F pressing the switch 14 and an operation stroke S deteriorates. As a result, operational feeling of the operating knob 54 is impaired. Moreover, there is a demand for using the space above the circuit board 12 effectively. However, a guide mechanism for guiding the pusher 56 occupies the space above the circuit board 12, making it impossible to use the space for other purposes in other ways.
In view of the aforementioned facts, an object of the present invention is to provide a switch operating mechanism, which has an operating knob that gives the operator an improved operational feeling and, at the same time, meets the demand for effective use of the space above the circuit board.
A first aspect of the present invention is a switch operating mechanism for turning a switch on and/or off by pressing the switch, which is provided at a circuit board, the mechanism comprising: an operating knob, which has a front end and a back end and is rotatably supported by a spindle that is provided at a lower position than the switch; and a pusher having a base, a first pressing arm, and a second pressing arm, the first pressing arm and the second pressing arm extending parallel to each other from both ends of the base in a direction perpendicular to an axial direction of the base such that the pusher has a substantial U-shape when seen in side view, wherein the switch of the circuit board is disposed between the first and the second pressing arms of the pusher, the first pressing arm being positioned directly above the switch and able to press the same; the operating knob is disposed such that the front end thereof is disposed between the circuit board and the second pressing arm so that the front end is able to press the second pressing arm; and when the back end of the operating knob is moved upward, the front end thereof moves the second pressing arm of the pusher downward, whereby the pusher moves linearly along a direction perpendicular to the plane of the circuit board, and the first pressing arm of the pusher presses the switch to turn the switch on and/or off.
In the switch operating mechanism of the first aspect of the present invention, when the operator moves the operating knob upward, the operating knob rotates and the front end thereof moves the second pressing arm of the pusher downward. Thus, the pusher moves linearly along the direction perpendicular to the plane of the circuit board, and the first pressing arm of the pusher presses the switch to turn the switch on and/or off.
In the switch operating mechanism, the operating knob is supported by the spindle, which is disposed at a lower position than the switch, and the pusher is formed in a substantial U-shape when seen in side view. Accordingly, even if the front end of the operating knob (the portion of the operating knob that presses the second pressing arm of the pusher) moves along an arcuate path around the spindle, the linear movement of the pusher presses and activates the switch. Thus, operational feeling of the operating knob, i.e., a relationship between a force pressing the switch and an operation stroke can be much closer to an ideal relationship. Further, in the switch operating mechanism, the switch of the circuit board is disposed between the first and the second pressing arms of the pusher. Accordingly, a guide mechanism for guiding the pusher may be provided along the base of the pusher (at the base side of the pusher). In other words, it is not necessary to provide the guide mechanism above the circuit board, whereby the space above the circuit board can be used effectively.
A second aspect of the present invention is a switch operating mechanism provided in a vehicle, for turning a switch on and/or off by pressing the switch provided at a circuit board, the mechanism comprising: an operating knob, which has a front end and a back end and is rotatably supported by a spindle that is provided at a lower position than the switch; and a pusher having a base, a first pressing arm, and a second pressing arm, the first pressing arm and the second pressing arm extending parallel to each other from both ends of the base in a direction perpendicular to an axial direction of the base such that the pusher has a substantial U-shape when seen in side view, wherein the switch of the circuit board is disposed between the first and the second pressing arms of the pusher, the first pressing arm being positioned directly above the switch and able to press the same; the operating knob is disposed such that the front end thereof is disposed between the circuit board and the second pressing arm so that the front end is able to press the second pressing arm; and when the back end of the operating knob is moved upward, the front end thereof moves the second pressing arm of the pusher downward, whereby the pusher moves linearly along a direction perpendicular to the plane of the circuit board, and the first pressing arm of the pusher presses the switch to turn the switch on and/or off.
A third aspect of the present invention is a method of manufacturing a switch operating mechanism for turning a switch on and/or off by pressing the switch, the method comprising the steps of: a. manufacturing a operating knob having a front end and a back end; b. manufacturing a pusher having a base, a first pressing arm, and a second pressing arm, the first pressing arm and the second pressing arm extending parallel to each other from both ends of the base in a direction perpendicular to an axial direction of the base such that the pusher has a substantial U-shape when seen in side view; c. mounting the operating knob to a spindle provided at a lower position than the switch so as to rotate about the spindle; and d. disposing the switch and the front end of the operating knob between the first pressing arm and the second pressing arm.